Metallurgical furnace



Dem V7 1935 L. s. LONGENEQKER 224,649

METALLURGI CAL FURNAC E ww-Aww INVENTOR @QQ E7 3935 i,... s. LONGNEQKEF@ 29249549 METALLURGICAL FURNACE Filed Jan, 22. 1934 3 Sheets-Sheet 2 INVENTOR L. S. LONGENECKER METALLURGIGAL FURNAGE 1% iBS.

Filed Jan. 22, 1934 3 Sheets-Sheet .'5

lill llll l| INVENTOR I HL Patented Dec. 17, 1935 UNHTED STATES iJATENT FFiE 1 Claim.

This invention relates to furnaces, and more particularly to furnaces of the type in which the material or batch to be heated or melted is charged through doors in the front wall thereof.

In the prior art, heating and open hearth furnaces have been charged through a plurality of charging door spaced lengthwise of the furnace front wall. Because of the construction of the roof or arches of these prier art furnaces, space limitations have made it impossible to make the charging doors large enough to facilitate easy and quick charging of the heating or melting chamber. Furthermore, the narrowness and spacing of these doors has made uniform distribution of the charge throughout the heating or melting chamber impossible, so that when a complete charge has been placed in the furnace, the passageway through which burning gases passed was choked and obstructed by the charge. Such choking and obstruction of the gas passage resulted in slow heating or melting performance, inefcient operation and utilization of the hearth area and severe abuse of the refractories in the arch.

In these prior art furnaces, the charging doors were separated by short wall sections, usually denominated door jambs, and spanned by short sprung door arches. On account of the severity of the service, frequent repairs and replacements of the door iambs and door arches was necessary,7 with a resulting loss of use of the furnace during the period required for the cooling down, making of the repairs, and the reheating of the furnace.

An object of this inventicn is the provision of a furnace of the character above-described, that shall be so designed and constructed that door jambs and door arches may be eliminated and the space which they would ordinarily occupy, made available for use as charging opening.

Another obiect of the invention is the provision of a furnace of the character referred to above7 having a charging door opening that is equal to, or less than the length of the heating chamber and greater in length than the width of a prior art charging door, including the door jambs.

A further object of the invention is the provision of a furnace having a charging door or doors of such height width that the furnace may be charged at a higher rate of speed and with more efficient use of the hearth area than has heretofore been possible, in prior art furnaces, and without choking the flow of burning gases through the charging chamber of the furnace.

And a still further object of the invention is the provision of a furnace having a long continuous charging opening in the front wall of the furnace and a plurality of individually operable doors for covering and uncovering said opening either in whole or in part, whereby mass charging of the furnace may be accomplished easily and quickly, and whereby the charge may be uniformly distributed throughout the charging chamber.

Other objects of the invention will, in part, be apparent, and will, in part, be obvious from the following description taken in conjunction l5; with the accompanying drawings, in which:

Figure l is a view in transverse section taken through the; heating or charging chamber of a metallurgical furnace arranged and constructed in accordance with an embodiment of the in- 2Q vention;

Fig. 2 is a fragmentary view in elevation of the front of the furnace shown in Fig. l, drawn to reduced scale, showing the charging doors in closed position, their open positions being indicated by broken lines;

Fig. 3, is an enlarged fragmentary top plan View of the furnace shown in Figs. l and 2.

Fig. 4 is a view in front elevation of a charging door frame embodied in the furnace shown in Figs. 1 and 2;

Fig. 5 is an enlarged fragmentary view of the furnace showing a charging door in section, taken on a plane through line V-V of Fig. 4;

Fig. 6 is a full sectional view of a door taken 35 on a plane through line VI-VI of Fig. 4 and a fragmentary sectional View of two charging doors, disposed one on each side thereof; and

Figs. 7 and 8 are side and front elevational views of a hanger employed to secure the re- 4 fractory blocks of the charging doors to the door frame of Fig. 4.

Throughout the drawings and the specification, like reference characters indicate like parts.

In the drawings, a metallurgical furnace I is shown having a back wall 2, a front wall 3, in which a charging door opening i is framed and which extends lengthwise of the furnace uninterruptedly for a distance which may be approXimately equal to or less than the length of the charging or heating chamber E of the furnace, but greater in length than the width of a prior art door including the door jambs. The furnace includes an arch E which is suspended from a superstructure composed of a plurality of I-beams I extending crcsswise of the furnace. The ends of beams l extending to the back wall of the furnace are mounted on a structural steel member such as an angle bar, which is secured to uprights or buckstays 9. The ends of beams 'I at the front of the furnace are secured to a beam II ruiming lengthwise of the furnace and which is supported on columns (not shown).

The arch or roof herein illustrated comprises a plurality of collaterally arranged courses I2 and I2 of refractory blocks which are individually suspended from the transverse beams 1, by means of main and auxiliary hangers I3 and I4.

As may be seen in Fig. 1, the refractory blocks in courses I2 are of the same length, while the blocks in courses I2 immediately adjacent the front wall of the furnace are longer so as to define the proper height of charging door opening. A lintel I5 extending lengthwise of and above the charging door opening is supported from beam II and forms a seal with the upper edges of a plurality of individually suspended doors I6. These doors as shown in Fig. 2, are individually suspended from cables I'I and bales I8 secured to the tops of the doors. Each cable I'I operates on pulley I9 so that these doors may be raised or lowered to open or close opening 4. As these doors move vertically, they slide on the front face of the door lintel I5 which serves as a bearing therefor as well as a seal as mentioned above.

In constructing roof 6 of the furnace herein illustrated, any type of suspended roof may be employed, but I prefer to employ a roof which is constructed in accordance with the teachings of my United States Patents Nos. 1,590,303,

granted June 29, 1926, and 1,913,168, dated June The blocks shown in these patents are provided with triangularly shaped tongues 29 on one face thereof and similarly shaped and positioned grooves in the opposite face thereof. As disclosed in my second-mentioned patent, these tongues and grooves interlock in such fashion that the individual auxiliary hangers herein designated at I4 are protected from leakage gas ames and heat radiated from the heating or melting chamber of the furnace. As disclosed in my first-mentioned patent, these tongues and grooves, being of the shape illustrated, prevent roken ends of blocks from dropping into the furnace.

The doors I6 herein illustrated each include a metallic support frame 22 having open sides, a vertical wall section 23 having top and bottom. plates 24 and 25 extending inwardly therefrom and at substantially right angles thereto. In practise it is preferred that these door frames be cast as a single unit.

As shown in Figs. 4, 5, and 6, the vertical Wall section 23 of these doors is of skeleton formation and comprises vertical members or risers 21; connected at their upper and lower ends to the top and bottom plates 24 and 25 and to each other by horizontal, vertically spaced ribs 28. The vertical members 21 are formed with relatively narrow vertical continuous slots 28 that terminate at their upper ends in relatively wide slot portions 29.

The inner faces of these door frames are lined with vertically disposed courses of refractory blocks 39 of substantially the same shape and formation as the blocks utilized in the roof or arch 6 of the furnace, and these blocks are secured to the door frame with individual hangers 30. The inner ends of these hangers are formed with Ts that nest in and interlock with T-shaped slots or grooves 3| formed in the outer 5 ends of these blocks. The outer end of each hanger is supplied with lugs 32 which are wider than the vertical slots 28 but narrower than the wide slot portions 29 so that by inserting the outer ends of these hangers through the large or 10 wide slot portions 29, and then moving the block with its hanger downwardly towards the bottom plate, the vertical courses of blocks may be layed up and each block tied to the Vertical wall section of the door frame. Thus the door lining l5 is positively anchored and prevented from falling into the furnace. The weight of the vertical courses of the blocks embodied in the lining of each door is carried by the bottom plate 24 of the door. A wear plate 34 secured to the bottom 20 plate 24 by any appropriate means, such as screws or bolts 35, may be employed to take the wear occasioned by the door resting on the threshold plate of door opening 4, and thereby protect the bottom plate of the door frame. 25

In order to seal the joints between adjacent doors, a plate 36 is bolted or otherwise secured to the left hand vertical edge flange 31 of each door frame, as seen in Fig. 6, which plate overlaps a similar flange 38, at the right vertical 30 edge of each door frame. By this form of construction the spaces between adjacent door sides are sealed.

As mentioned previously herein, the doors are independently mounted for vertical movement, 85 and provided with means for so buiding them that they are maintained in alinement and prevented from swinging either toward or from the furnace front. A convenient guiding means is illustrated in Fig. 2, which comprises a cable S9 40 stretched across the doors I6 near their lower ends. This cable operates over pulleys 40 supported on either side of the door opening 4 and is counterweighted at each end by weights 4I. The cable is connected to each door by upwardly 45 curved lugs 42 so that when any door is raised the cable is lifted with it, as indicated by the broken line position 43 but holds the door in alinement with the other doors. If all of the doors are raised the cable moves upwardly with 50 them, as indicated by the broken line position 44 of the cable and doors. While a particular form of door guiding means has been illustrated, it will be apparent that various modifications thereof may be made or that different mecha- 55 nisms may be employed to maintain the doors in alinement.

With my improved furnace, a charging door of the length herein mentioned may be employed which is not obstructed by door jambs 60 or arches. The expense of maintenance and repairs of these door jambs and arches, and the consequent loss of furnace operating time which such repairs involve, is avoided. Aside from this, the furnace may be charged more 65 quickly and efliciently because of the increased size of door opening which my improved furnace provides. The material charged may be distributed evenly over the furnace hearth both as to area and depth so that choking of the flow of gases through the furnace may be avoided. By avoiding such choking, the charge may be heated or melted at a higher and more efcient rate than was heretofore possible with prior art furnaces.

While but a single embodiment of the invention has been disclosed herein, it will be apparent that various changes and modifications may be made therein Without departing either from the spirit or the scope of the invention.

What I claim as new and desire to secure by Letters Patent is:

A metallurgical furnace having a charging opening in the front wall extending lengthwise of the furnace for a distance approximately equal to the length of the charging space of the furnace, a plurality of individually operable doors for said opening, individually supported vertically movable doors for said charging opening providing for partial or full length closing or uncovering of said opening, pulleys at the ends of said charging opening, and means including a counterweighted cable carried by said doors and operating over said pulleys for guiding said doors and maintaining them in alinement when moved to open or closed positions.

LEVI S. LONGENECKER. 

